Fluid-gage and process of manufacturing the same.



G. F. HIGGINS.

FLUID GAGE AND PROCESS OF MANUFACTURING THE SAME. APPLICATION FILED SEPT. I3, 1915.

L2TL58 Patentedsept. 3,1918I.

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G. F. HIGGINS. FLUID GAGE AND PROCESS OF MANUFACTURING THE SAME.

APPLICATION FILED SEPT. I3, I915. 1,2775%. Patented Sept. 3,1918.

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GEORGE E. HIGGINS, 0F MELROSE, MASSACHUSETTS, ASSIGNOR TO GEM STAMPED STEEL COMPANY, A CORPORATION OF MASSACHUSETTS.

FLUID-GAGE AND PROCESS OF MANUFACTURING THE SAME.

Application filed $eptember 13, 1915.

To all whom it may concern:

Be it known that I, GEORGE F. HIGGINS, a citizen of the United States, residing at Melrose, in the county of Middlesex and State of Massachusetts, have invented cer-.

tain new and useful Improvements in Fluid- Gages and Processes of Manufacturin the Same; and I do hereby declare the follow ing to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to a process of making fluid gages, and more particularly to fluid gages of that type which comprise a cap containing a dial and pointer, a float and suitable connections for actuating the pointer, and a float guiding tube secured to the cap andprovided with a helical float guiding slot.

As heretofore constructed the tube portion of a gage of this type has been seamless and the helical slot has been out by means of a machine tool. For this reason gages of this type have been expensive to manufacture and furthermore, on account of the necessity of making the helical slot of uniform pitch throughout its length their use has been limited to tanks of certain shapes.

The object of the present invention is to provide an improved process for manufacturing float gages of the type above referred to and particularly the float guiding tubes of such gages, whereby gages of this type may be easily and cheaply produced which will operate in an accurate and reliable manner to indicate plainly the difierences of fluid level in tanks of widely differing shapes.

With the above object in view the present invention contemplates forming the float guiding tube of a substantially rhomboidal shaped blank by rolling the blank about an axis extending longitudinally of the blank at right angles to its ends and securing the blank in rolled position with its side edges separated to form a helical float guiding slot. The outline of the blank will depend upon the diameter of tube desired, the total amount of angular movement to be given to the float and through the float to the pointer, the depth of the tank in which the gage is to be used, and the shape of the tank.

Specification of Letters Patent.

Patented Sept. 3, 1916. Serial No. 50,470.

Referring to the drawings annexed Figure 1 is a vertical central section of the f Fig. 2 1s a plan of the gage;

Fig. 3 is a detail section showing the parts of the head disassembled.

Fig. 4 is a section showing a step in the process of expanding the locking washer;

Fig. 5 is a plan of a blank for a tube;

Fig. 6 is a side elevation of a tube;

Fig. 7 is a detail showing the fastening of the pointer support to the rod, and

Fig. 8 is a cross-section.

The gage illustrated in the drawings comprises a suitable cap Or index casing member 2 of well known or suitable construction, having a threaded portion 3 adapted to be screwed into a fitting upon the tank on which the gage is to be employed, and having a central longitudinal bore f and a slightly enlarged chamber portion at the top to receive a dial 6 which is supported upon an annular shoulder 7. The cap is internally grooved at 8 to receive an expansion spring or snap ring 9 provided for the purpose of retaining the dial in position on the shoulder 7. The dial is suitably indexed on its face to show the quantity of fluid in the tank. Above the shoulder 7 the cap member 2 is bored slightly larger to form a shoulder 10 upon which is placed a transparent guard or window 11 which is maintained in place by an expansion snap ring adapted to snap into an under-cut groove 13 provided for its reception in the upper or rim portion of the cap member :2. Interposed between the dial 6 and the window glass 11 is a turnable pointer 14 which is secured to the reduced upper end of a support 15 attached to the upper end of a flat rod 16 which depends from the cap and passes through a guide tube 17 which is secured upon a float 18 adapted to move vertically with variations of level of fluid in the tank upon which the gage may be installed.

The device or support 15 is'attached to the upper end of the flat rod or wire 16 by slitting the lower end of the support 15 as at 19 to receive the end of the flat rod 16, and when this is assembled in the support 15 the latter is hammered or pinched down as indicated at 20 to firmly clench. the inserted end of the rod 16. One of the ends of the tube 17, which may be of cylindrical stock, is flattened somewhat as at 21, to embrace the rod 16 to permit the sliding of the parts relatively but to insure their uniform rotation together.

The parts above described are or may be constructed and arranged to operate as is usual in this type of float gage.

I In the illustrated embodiment of the present invention the float 18 is turned angu larly as it slides along the rod 16 by a slotted guide tube 22 formed from the blank indicated in Fig. 5 at 23. The blank has the general form of a rhomboid and when rolled about an axis extending longitudinally of the blank at right angles to its end edges is adapted to form the tube 22 as indicated in Fig. 6. By securing the blank in rolled position with the parallel side edges 2% separated the helical float guiding slot 25 is formed. It will be obvious that the width of the blank. 23 is determined by the diameter of tube desired and that the height of the blank, or in other words, the distance between its end edges, will be determined by the depth of the tank. Inasmuch as the blank is rolled about an axis at right angles to the end edges the distance which the helical slot 25 extends around the tube will depend upon the amount to which the upper end of the blank is offset laterally with relation to the lower end. Accordingly, the end edges of the blank are offset laterally with relation to each other a distance determined by the extent of the total angular movement which is to be given. to the float and through the float to the indicating pointer. In Fig. 5 the total angular movement imparted to the float and the rate of angular movement at different portions of its travel along the helical slot are indicated by the rectilinear scale below the blank, which scale is a development of the scale of the dial. The vertical dotted line from the left hand end of this scale to the point (Z at the upper end of the blank indicates that the total angular movement to be imparted to the float is approximately three quarters of a full revolution. While it is not necessary that the graduations on the dial be uniformly spaced, it is desirable to avoid undue crowding of the graduations at any point. It is also desirable that the pitch of the helical slot be as nearly uniform as pos sible throughout its length in order to avoid undue friction of the float against the walls of the slot at any point in the travel of the float. By varying the contour of the side edges 24, any desired form of helical slot 25 may be obtained so that with any shape of tank the desired angular movement of the float may be secured at any portion of its travel so that all the graduations on the dial may be spaced the desired distance apart. In some forms of tank the desired rate of angular movement will be imparted to the float when the blank 23 is formed with straight side edges 24, as indicated in Fig. 5, but with other forms of tanks superior results will be obtained when the parallel side edges 2st are curved or irregular. With the blank illustrated in Fig. 5 the float is designed to be at the point a when the tank is one quarter full, at the point 6 when the tank is one half full, and at the point a when the tank is three quarters full, as will be obvious without further description.

\Vhen the blank 23 is rolled into a tube, as above described, the proximity of the edges 2 1 will be determined by a shoulder 26 near the upper end of the blank and by a shoulder 27 near the lower end of the blank but on the opposite side edge. At the upper end of the blank 23 the side edges are formed vertical, as indicated at 28, and at the lower end of the blank the side edges are also formed vertical, as indicated at 29. The upper vertical edges 28 are longer than the lower vertical edges 29 and after the blank has been rolled to form the tube 22 a further step in the process consists of securing the upper portion of the tube with a cylindrical clamp band or collar 30 which holds the adjacent and abutting edges 28 of the blank in close relation and which ring may be soldered or otherwise fastened over the upper end of the tube and adjacent the upper end of the slot 25. Afurther step in the process of making and assembling the gage consists of locking the tube end firmly in the cap by expansion, which permits of both rapid and cheap work and in the accomplislnnent of this connection the tube is expanded into a seat or groove 32 in the cap member 2 by a washer 33 which is preferably cup-shaped. The washer is placed in the interior of the tube 22 and alined with the groove 32 and is then flattened by suitable means, as, coacting plungers indicated in dotted lines at 3435 (Fig. 1) which act to expand the washer 33 until it firmly presses the tube 22into the complemental seat 32 of the cap 2. This method and means for interlocking the tube 22 to the cap 2 is not only simple and inexpensive but provides an extremely rigid fastening of these two? parts together.

After the tube 22 has been attached to the cap member 2 the float 18 is then assemtube 22 is contracted so that the perpendicular edges 29 abut and are held against expansion by a flanged closure 37 which may be soldered or otherwise secured in place over the tube. The closure is preferably flanged to overlap the exterior surface of the tube and is provided with a central aperture 38 in which the lower projecting end of the rod 16 may rotate and is guided. To provide for the free flow of liquid to and from the tube 22 and for the purpose of permitting the escape of sediment or foreign material which may collect in the tube on the lower closure 32 the latter is provided with a plurality of apertures 39.

The invention having been thus described, what is claimed is 1. The process of making a guiding tube for a float gage which consists in forming a rhomboidal-shaped blank with end edges offset laterally with relation to each other a distance determined by the extent of the total angular movement to be given the float and separated from each other a distance determined by the depth of the tank in which the gage is to be used, rolling the blank into tubular form about an axis ex tending longitudinally of the blank and at right angles to its ends, and securing the blank in rolled position with its side edges separated to form a helical float guiding slot.

2. The process of making a guiding tube for a float gage which consists in forming a rhomboidal-shaped blank with side edges having a contour determined by the rate of angular movement to be given to the float in different portions of its travel and with end edges offset laterally with relation to each other a distance determined by the extent of the total angular movement to be given to the float, and separated from each other a distance determined by the depth of the tank in which the gage is to be used, rolling the blank into tubular form about an axis extending longitudinally of the blank and at right angles to its ends, and securing the blank in rolled position with its side edges separated to form a helical float guiding slot.

3. The method of making a float guidetube of the type set forth, consisting in first forming a sheet blank having oblique parallel side edges of equal length terminating short of the ends of the blank, the remaining portions of the side edges lying at an angle to said oblique edges, and also to the end edges of the blank, these terminal portions of the side edges at each end of the blank being parallel with each other and one being offset to form a shoulder facing toward the opposite end of the blank; then curling the blank int-o tubular form about an axis at right angles to said end edges until said terminal portions of the side edges abut, said shoulders serving not only to space said oblique portions of the side edges away from each other to form a helical slot but also to close the ends of the slot.

4. A fluid gage comprising a cap with a gage dial, a pointer movable thereover, a float, means whereby the float is connected to the pointer to rotate the same, and a float guiding tube secured to the cap, consisting of a rho1nboidal-shaped blank rolled into tubular form about an axis extending longitudinally of the blank and at right angles to its ends, and having its side edges separated to form a helical float guiding slot.

5. As an article of manufacture, a float guide-tube of the class set forth, consisting of a metal sheet rhomboidal in shape, curled longitudinally to form a cylindrical tube, the oblique edges being provided with offset abutting portions at their ends and being spaced apart by said offset abutting portions to form a helical slot, these ofiset portions serving also to close the ends of the slot.

GEORGE F. HIGGINS.

Copies of this patent may he obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. 0, 

